Method for searching pilot signals to synchronize a CDMA receiver with an associated transmitter
AssigneeIPR Licensing, Inc.
InventorsJames A. Proctor, Jr., Antoine J. Rouphael, John E. Hoffmann, George R. Nelson, Jr.
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Abstract
A method for synchronizing a CDMA receiver to a transmitter when an adaptive antenna is utilized to receive transmitted data, wherein a receiving antenna system is adapted between a 360° reception angle pattern (i.e., an omni-directional pattern) and a fixed reception angle (i.e., a directional pattern) by permitting the receiver to identify a pilot signal having the largest magnitude. The receiver minimizes interference from other pilot signals by steering antenna pattern nulls toward other transmitters. As a result, the time required for the receiver to acquire a valid pilot signal is significantly reduced.
Claims2
An apparatus for searching for a pilot signal and optimizing reception of the pilot signal in wireless communications, comprising:
- a steerable antenna comprising a plurality of antenna elements;
- phase shifters coupled to respective antenna elements, the phase shifters configured to steer the antenna;
- a pseudorandom noise (PN) sequence generator, configured to generate a PN sequence as output;
- a modulator, configured to receive demodulated in-phase (I) and quadrature (Q) signals and modulate the I and Q signals with the output of the PN sequence generator;
- a first integrator configured to integrate the modulated I signal;
- a second integrator configured to integrate the modulated Q signal;
- a first squarer configured to square an output of the first integrator;
- a second squarer configured to square an output of the second integrator;
- a summer configured to add outputs of the first and second squarers;
- a third integrator configured to integrate an output of the summer;
- and
- a threshold circuit configured to set a plurality of thresholds and determine if an output of the third integrator exceeds at least one of the thresholds.
Dependencies are inferred from the claim text.